Cooktop



FIG. 1 is a frontal perspective view of the cooktop showing the new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is a right side elevational view thereof.

The broken line showing the unornamental bottom of the cooktop is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a cooktop, as shown and described. 